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E-HELP: Adding Contacts to the SRM

Q: The SRM Safety Relay Module only has three contacts. Is it possible to add extra contacts? Also, is there specific wiring required to obtain a SIL 2 rating?

A: You can connect a wetted contact to the power terminals of two SRMs in order to have more than three contact outputs. Connect jumper wires to the input terminals of these SRMs. The wetting current must be sufficient to drive the coils of the two SRMs.

The SRM installation manual has detailed directions for installation in Safety Instrumented Systems (SIS) as well as information about connecting the coil (input) side to either dry or wetted contacts. In addition, Figure 5.3 in the manual shows how to connect a wetted contact to a single SRM.